Stocks extended losses on Monday, with the S&P 500 briefly falling more than 5 percent in the first session since Standard & Poor's cut the United States' top-tier AAA credit rating, with banks among the biggest drags.

The Dow Jones industrial average dropped 427.01 points, or 3.73 percent, to 11,017.60. The Standard & Poor's 500 Index slid 57.83 points, or 4.82 percent, to 1,141.55. The Nasdaq Composite Index tumbled 122.39 points, or 4.83 percent, to 2,410.02.

(Reporting by Chuck Mikolajczak; editing by Jeffrey Benkoe)